Method for treating anxiety and mood disorders in older subjects

ABSTRACT

The present invention is a method for treating anxiety or mood disorders in elderly subjects comprising administering to the subject exhibiting an anxiety or mood disorder an effective amount of an agent that modulates Aβ in the subject.

This invention relates to methods of treating certain mental disordersin elderly subjects.

Millions of older people—indeed, the majority—cope constructively withthe physical limitations, cognitive changes, and various losses, such asbereavement, that frequently are associated with later life. Thecapacity for sound mental health among older adults notwithstanding, asubstantial proportion of the population 55 and older—almost 20 percentof this age group—experience specific mental disorders that are not partof “normal” aging. The data below represent the 1-year prevalence (%) ofvarious mental disorders among Americans above age 55. In the samestudy, the prevalence of any mental disorder was 19.8% and theprevalence of severe cognitive impairment was 6.6%. % % any anxietydisorder 11.4 any mood disorder 4.4 simple phobia 7.3 major depressiveepisode 3.8 social phobia 1.0 unipolar major depression 3.7 agoraphobia4.1 dysthymia 1.6 panic disorder 0.5 schizophrenia 0.6obsessive-compulsive disorder 1.5 other 0.6

Depression in older adults not only causes distress and suffering butalso causes impairments in physical, mental, and social functioning, andincreased mortality, especially from suicide, heart disease and possiblycancer. Estimates of the prevalence of major depression and itsassociation with age and other factors vary widely, depending on thedefinition and the procedure used for counting persons with depression.The prevalence of major depression is thought to decline with age, whiledepressive symptoms increase (symptoms that now might warrantclassification as minor depression). Older people often present severaldepressive symptoms together, a condition often referred to as “minordepression,” that can be as disabling as major depression. Minordepression, despite the implications of the term, is major in itsprevalence and impact. Eight to 20 percent of older adults and up to 37percent in primary care settings suffer from depressive symptoms. Inlate life, the course of depression tends to be more chronic than thatin younger adults with longer recurrent episodes punctuated by shorterremissions, and highly variable response to treatment. Response rates totreatment are thought to be somewhat successful (between 60 and 80percent), but the response generally takes longer than that for youngeradults.

The most serious consequence of depression in later life—especiallyuntreated or inadequately treated depression—is increased mortality fromeither suicide or somatic illness. Older persons (65 years and above)have the highest suicide rates of any age group. Suicide in older adultsis most associated with late-onset depression. Among patients 75 yearsof age and older, 60 to 75 percent of suicides have diagnosabledepression.

Depression in the elderly leads to increased mortality from otherdiseases, such as heart disease and cancer. In the case of myocardialinfarction, depression elevates mortality risk fivefold. Chronicdepression (lasting an average of about 4 years) raises the risk ofcancer by 88 percent in older people.

Late-life depression is particularly costly because of the excessdisability that it causes and its deleterious interaction with physicalhealth. Older primary care patients with depression visit the doctor andemergency room more often, use more medication, incur higher outpatientcharges, and stay longer at the hospital.

Known pharmaceutical agents for treating depression in the elderly varyin their effectiveness, and all suffer from side effects that areespecially worrisome in this population. Tricyclic antidepressants(TCAs), for example, have been widely used to treat elderly depressedpatients, but anticholinergic effects such as dry mouth, urinaryretention, and constipation lead to severe problems in older adults,such as bowel impaction due to persistent constipation or prevention ofthe wearing of dentures because of dry mouth. The anticholinergiceffects of the TCAs may also cause tachycardia or arrhythmias and canfurther compromise preexisting cardiac disease. Central anticholinergiceffects may result in acute confusional states or memory problems in thedepressed older adult. Orthostatic hypotension, which may lead to fallsand hip fractures, is also a concern when the TCAs are administered.

Selective serotonin reuptake inhibitors (SSRIs) have feweranticholinergic and cardiovascular side effects than the TCAs, but thisis counterbalanced by a significant potential for drug-druginteractions. This is of clinical importance since older adults commonlyreceive a large number of medications. The SSRIs vary in theirinhibition of the cytochrome p450 family of isoenzymes. Newer non-SSRIantidepressants are often suggested for treating later life depressionbecause their side effects are better tolerated by older adults.

Clinical use of monoamine oxidase inhibitors is often restricted topatients who are refractory to other antidepressant drugs because ofpotentially life-threatening pharmacodynamic interactions withsympathomimetic drugs or tyramine-containing foods and beverages. Thesympathomimetic amines (e.g., phenylpropanolamine and pseudoephedrine)may be present in over-the-counter decongestant products that olderpatients are prone to self-administer. An additional concern is the riskof orthostatic hypotension, which occurs even at therapeutic doses.Bupropion, though generally well tolerated, requires added cautionbecause of an increased risk of seizures.

Information about the course and treatment of anxiety lags behind thatof other common mental conditions in the elderly, such as depression andAlzheimer's. Anxiety is at least as common in the old as in the young,although how and when it appears is distinctly different in olderadults.

Overall, community-based prevalence estimates indicate that about 11.4percent of adults aged 55 years and older meet criteria for an anxietydisorder in 1 year. Phobic anxiety disorders are among the most commonmental disturbances in late life. Anxiety symptoms that do not fulfillthe criteria for specific syndromes are reported in as many as 17percent of older men and 21 percent of older women.

Drugs used to treat anxiety disorders overlap significantly with thoseused to treat depression, and include selective serotonin reuptakeinhibitors (SSRIs), tricyclic antidepressants, benzodiazepines, betablockers, and monoamine oxidase inhibitors (MAOIs). Benzodiazepines aremarginally effective at best in treating chronic anxiety in olderpatients. The half-life of certain benzodiazepines and their metabolitesmay be significantly extended in older patients (particularly for thecompounds with long half-life). If taken over extended periods, evenshort-acting benzodiazepines tend to accumulate in older individuals.Thus, it is generally recommended that any use of benzodiazepines belimited to discrete periods (less than 6 months) and that long-actingcompounds be avoided in this population. Side effects of benzodiazepinesmay include drowsiness, fatigue, psychomotor impairment, memory or othercognitive impairment, confusion, paradoxical reactions, depression,respiratory problems, abuse or dependence problems, and withdrawalreactions. Benzodiazepine toxicity in older patients includes sedation,cerebellar impairment (manifested by ataxia, dysarthria, incoordination,or unsteadiness), cognitive impairment, and psychomotor impairment.Psychomotor impairment from benzodiazepines can have severeconsequences, leading to impaired driver skills, motor vehicle crashes,and falls.

Buspirone, an anxiolytic (antianxiety) agent that is chemically andpharmacologically distinct from benzodiazepines may require up to 4weeks to take effect, and significant adverse reactions to buspirone arefound in 20 to 30 percent of anxious older patients, including mostfrequently, gastrointestinal symptoms, dizziness, headache, sleepdisturbance, nausea/vomiting, uneasiness, fatigue, and diarrhea.

Thus, it can be concluded from this brief survey of anxiety and mooddisorders in older persons that these are serious and costly conditionsfor which current pharmaceutical agents provide varying degrees ofeffectiveness, but often with risky adverse reactions and a realpossibility of adverse interactions with the many other agents thatolder people commonly use for other ailments. There is an increasingneed as many populations age for new pharmaceutical agents that areeffective in treating anxiety and mood disorders in the elderly, andthat are more compatible with the many other medications that theelderly commonly receive for other diseases and conditions.

Alzheimer's disease (AD), a disorder of pivotal importance to olderadults, strikes 8 to 15 percent of people over the age of 65.Alzheimer's disease is one of the most feared mental disorders becauseof its gradual, yet relentless, attack on memory. Memory loss, however,is not the only impairment. Symptoms extend to other cognitive deficitsin language, object recognition, and executive functioning.

Behavioral symptoms—such as psychosis, agitation, depression, andwandering—are common and impose tremendous strain on caregivers. Of thebehavioral symptoms experienced by patients with Alzheimer's disease,depression and anxiety occur most frequently during the early stages,while psychoses occur later. Though behavioral symptoms have receivedless attention than cognitive symptoms, they have serious ramifications,such as, patient and caregiver distress, premature institutionalization,and significant compromise of the quality of life of patients and theirfamilies. Alzheimer's disease, especially its behavioral symptoms,appears to place patients at risk for abuse by caregivers. Forty tofifty percent of Alzheimer's patients have symptoms of depression andthe depression accelerates loss of functioning in everyday activities.Depression in Alzheimer's is different from other depressive disorders[Olin, et al., Am. J. Geriatr. Psychiatry 10:125-128 and 129-141(2002)]. Even modest reduction in behavioral symptoms can producesubstantial improvements in functioning and quality of life.

New therapies are being studied for their ability to ameliorate ormodify the significant memory loss that is characteristic of AD. Amongthem, lowering the levels of the Aβ peptide in the brain has beenproposed to ameliorate memory loss and improve cognitive abilities inanimal models of AD, and development of pharmaceutical agents to reduceAβ is in progress. Among the pharmaceutical approaches being studied forameliorating the effects of Aβ is the use of antibodies that bind Aβpeptide.

No link between the anxiety disorders and mood disorders discussed aboveand the Aβ peptide is known. Consequently, drugs potentiallyameliorating Aβ-related conditions and pathologies have not been testedwith regard to their effects on behavior, other than those associatedwith cognitive abilities.

I quite surprisingly found that when mice were injected twice within aweek before fear conditioning with an antibody that binds to Aβ peptide,they exhibited significantly reduced “long-body” posture, a behavioraltrait also called “stretch attend posture” in the literature. Thisbehavior is known to be elicited in rodents by pain or fear (e.g.electric shocks, or stimuli previously associated with the shocks, orstimuli associated with natural predators of rodents). This reduction,observed in elderly (11 months old) wild type and transgenic mice thatoverproduce Aβ in their brains, represents reduced fear or reducedanxiety, which is likely to also affect mood. Most notably, the effectof anti-Aβ antibody was significant both in transgenic mice and inwild-type mice. In summary, I have surprisingly discovered thatadministering an agent that modulates levels of Aβ to aged mice reducesanxiety in the mice, regardless of their status with respect to Aβ.

BRIEF SUMMARY OF THE INVENTION

Accordingly, the present invention is a method for treating anxietydisorders and mood disorders in an elderly subject, comprisingadministering to the subject an effective dose of an anti-Aβ antibody.

DETAILED DESCRIPTION OF THE INVENTION

The term “treating” includes prophylaxis (preventing), amelioration(reducing or reversing), or elimination of a sign, symptom, condition,disease, or disorder. “Anxiety disorder” is a generic term for disordersthat involve anxiety. The five major anxiety disorders are panicdisorder, obsessive-compulsive disorder, post-traumatic stress disorder,generalized anxiety disorder and phobias (including social phobia, alsocalled social anxiety disorder). Among the anxiety disorders that aretreated in the practice of the present invention include areobsessive-compulsive disorder, panic disorder, panic attack,agoraphobia, post-traumatic stress disorder, social phobia, disruptivebehavior disorder, and chronic fatigue syndrome.

Most of the disorders discussed here are described and categorized inthe DIAGNOSTIC AND STATISTICAL MANUAL OF MENTAL DISORDERS, (4th edition,1994), published by the American Psychiatric Association (hereinafterreferred to as DSM or DSM-IV). In the discussion below, the DSM codesfor the disorders will be given where appropriate.

Obsessive-compulsive disorder, DSM 300.3, is characterized by recurrentobsessions or compulsions that are severe enough to be time consuming orcause distress or impairment of the patient's life. Obsessions arepersistent ideas, thoughts, impulses or images that are recognized bythe patient to be intrusive and inappropriate and cause anxiety ordistress. The individual senses that the obsession is alien, not undercontrol and not the kind of thought that the patient would expect tohave. Common obsessions include repeated thoughts about contamination,repeated doubts, a need to arrange things in a particular order,aggressive or horrific impulses and sexual imagery. Compulsions arerepetitive behaviors, such as hand washing, or mental acts, such ascounting or repeating words silently, the goal of which is to prevent orreduce anxiety or distress. By definition, compulsions are eitherclearly excessive or not realistically connected with that which theyare designed to neutralize or prevent.

Panic attack, panic disorder and agoraphobia, categorized as DSM 300.01,300.21 and 300.22, are characterized by irrational sense of imminentdanger or doom, an urge to escape, or a fear of being in a situationfrom which escape might be difficult. The patient exhibits symptoms suchas palpitations, accelerated heart rate, sweating, sensations ofshortness of breath, chest pain, nausea, dizziness, fear of dying, andthe like, and may have such attacks very frequently.

Social phobia, DSM 300.23, produces a marked and persistent fear ofsocial or performance situations in which embarrassment may occur.Exposure to such a situation may result in a panic attack, or otheranxious response. Most often, patients with the disorder simply avoidsituations of the type that they dread, producing an obvious dislocationin the patient's life.

Post-traumatic stress disorder, DSM 309.81, afflicts patients followingexposure to a traumatic stress involving personal experience of an eventinvolving actual or threatened death of injury. Such traumatic eventsinclude experiences such as military combat, personal assault,kidnapping, terrorist attack, torture, natural or man-made disasters,severe accidents, or being diagnosed with a dreaded illness. Learningabout such events occurring to others, particularly a family member orclose friend, also may produce the disorder. Triggering events thatsymbolize the traumatic event, such as an anniversary, may recreate thestress and bring on the disorder long after the event is passed.Patients strive to avoid stimuli associated with the trauma, even to thepoint of amnesia or reduced responsiveness to other people in general.

Diagnosis of these disorders, or the identification of a patient at riskof one or more of them, is to be made by a physician or psychiatrist. Itis presently believed that administration of an effective dose of ananti-Aβ agent results in the alleviation of the effects of the disorderfrom which the patient suffers, or even the elimination of the disordercompletely. Diagnosis of anxiety disorders in the elderly may be aidedby careful inquiry, as described by Lang, A. J., et al., “AnxietyDisorders: How to Recognize and Treat the Medical Symptoms of EmotionalIllness,” Geriatrics 56: 24-27, 31-34 (2001). Likewise, diagnosis ofdepression and anxiety in Alzheimer's patients may be more challengingthan in other elderly patients. Recent diagnostic criteria fordepression in Alzheimer's disease will aid the diagnosis [Olin, et al.,Am. J Geriatr. Psychiatry 10:125-128 and 129-141 (2002)].

“Anxiety” means the subjective unpleasant feeling of nervousness ordistress in response to a feared situation (symptoms), sometimesaccompanied by physiological signs including nausea, trembling,breathlessness, sweating and increased heart beat. Mental disorderscharacterized by felt anxiety or related symptoms are classified as“Anxiety Disorders.” The ability of an agent to treat anxiety andrelated disorders may be demonstrated using the techniques describedhereinbelow or the well-known fear-potentiated startle and elevated plusmaze models of anxiety [e.g., Davis, Psychopharmacology, 62:1 (1979);Lister, Psychopharmacology, 92: 180-185 (1987); and U.S. Pat. No.5,750,566].

“Mood disorders” are mental disorders that involve mood, including,depression, major depressive episode, unipolar major depression,dysthymia, schizophrenia, and minor depression, late-onset depression,and traumatic grief,

“Depression” means behavioral inhibition in response to conflictingexperience, that manifests as increased immobility over a prolongedperiod of time, or that manifests also as reduced motivation to escapepunishment or work for reward. For humans, depression is a mental statecharacterized by extreme feeling of sadness, despair, hopelessness, lowself-esteem, extremely strong and unreasonable negative feeling.

Experiencing five or more of the following symptoms each day during atwo-week period or symptoms interfering with work or family activitiescan indicate the presence of clinical depression: prolonged sadness orunexplained crying spells; significant changes in appetite or sleeppatterns; irritability, anger, worry, agitation, or anxiety; pessimism;indifference; loss of energy or persistent tiredness; feelings of guiltor worthlessness; inability to concentrate; indecisiveness; inability totake pleasure in former interests; social withdrawal; unexplained achesand pains; or recurring thoughts of death and suicide.

The term “major depression” refers to conditions with a major depressiveepisode, such as major depressive disorder, bipolar disorder, andrelated conditions. Major depressive disorder, the most common type ofmajor depression in adults, is characterized by one or more episodesthat include the following symptoms: depressed mood, loss of interest orpleasure in activities, significant weight loss or gain, sleepdisturbance, psychomotor agitation or retardation, fatigue, feelings ofworthlessness, loss of concentration, and recurrent thoughts of death orsuicide. Major depressive disorder cannot be diagnosed if symptoms lastfor less than 2 months after bereavement, among other exclusionaryfactors (DSM-IV).

Most older patients with symptoms of depression do not meet the fullcriteria for major depression. The new diagnostic entity of minordepression has been proposed to characterize some of these patients.“Minor depression,” a subsyndromal form of depression, is not yetrecognized as an official disorder, though DSM-IV proposes furtherresearch on it.

Minor depression is more frequent than major depression in the elderly,with 8 to 20 percent of older community residents displaying symptoms.The diagnosis of minor depression is not yet standardized; the researchcriteria proposed in DSM-IV are the same as those for major depression,but a diagnosis would require fewer symptoms and less impairment. Minordepression, in fact, is not thought to be a single syndrome, but rathera heterogeneous group of syndromes that may signify either an early orresidual form of major depression, a chronic, though mild, form ofdepression that does not present with a full array of symptoms at anyone time, called dysthymia, or a response to an identifiable stressor.

Major or minor depression diagnosed with first onset later than age 60has been termed late-onset depression. Late-onset depression is not adiagnosis; rather, it refers to a subset of patients with major or minordepression whose later age at first onset imparts slightly differentclinical characteristics, suggesting the possibility of distinctetiology. Late-onset depression shares many clinical characteristicswith early-onset depression, yet some distinguishing features exist.Patients with late-onset depression display greater apathy and lesslifetime personality dysfunction. Cognitive deficits may be moreprominent, with more impaired executive and memory functioning andgreater medial temporal lobe abnormalities on magnetic resonanceimaging, similar to those seen in dementia.

Risk factors for late-onset depression, based on results of prospectivestudies, include widowhood, educational attainment less than highschool, impaired functional status, and heavy alcohol consumption.Late-life mental disorders are often detected in association withsomatic illness. The prevalence of clinically significant depression inlater life is estimated to be highest—approximately 25 percent—amongthose with chronic illness, especially with ischemic heart disease,stroke, cancer, chronic lung disease, arthritis, Alzheimer's disease,and Parkinson's disease.

Other risk factors associated with late-onset depression have beenidentified and may be used to identify subjects who will benefit fromthe present invention. Persistent insomnia, occurring in 5 to 10 percentof older adults, is a known risk factor for the subsequent onset of newcases of major depression both in middle-aged and older persons. Grieffollowing the death of a spouse, relative, or close acquaintance(discussed below) also is an important risk factor for both major andminor depression. A final pathway to late-onset depression, suggested bycomputed tomography and magnetic resonance imaging studies, may involvestructural, neuroanatomic factors. Enlarged lateral ventricles, corticalatrophy, increased white matter hyperintensities, decreased caudatesize, and vascular lesions in the caudate nucleus appear to beespecially prominent in late-onset depression associated with vascularrisk factors. These findings have generated the vascular hypothesis oflate-onset depression; namely, that even in the absence of a clearstroke, disorders that cause vascular damage, such as hypertension,coronary artery disease, and diabetes mellitus, may induce cerebralpathology that constitutes a vulnerability for depression.

Loss of a spouse, relative, or close acquaintance is common in latelife. Bereavement is a natural response to such death. Its features,almost universally recognized, include crying and sorrow, anxiety andagitation, insomnia, and loss of appetite. This constellation ofsymptoms, while overlapping somewhat with major depression, does not byitself constitute a mental disorder. On the other hand, bereavement isan important and well-established risk factor for depression. At least10 to 20 percent of widows and widowers develop clinically significantdepression during the first year of bereavement. Only when symptomspersist for 2 months and longer after the loss does the DSM-IV permit adiagnosis of either adjustment disorder or major depressive disorder.Even though bereavement of less than 2 months' duration is notconsidered a mental disorder, it still warrants clinical attention(DSM-IV). The justification for clinical attention is that bereavement,as a highly stressful event, increases the probability of, and may causeor exacerbate, mental and somatic disorders. Without treatment, suchlate-onset depressions tend to persist, become chronic, and lead tofurther disability and impairments in general health, includingalterations in endocrine and immune function.

Bereavement-associated depression often coexists with another type ofemotional distress, which has been termed traumatic grief. The symptomsof traumatic grief, although not formalized as a mental disorder inDSM-IV, appear to be a mixture of symptoms of both pathological griefand post-traumatic stress disorder. Such symptoms are extremelydisabling, associated with functional and health impairment and withpersistent suicidal thoughts, and may well respond to pharmacotherapy.Increased illness and mortality from suicide are the most seriousconsequences of late-life depression.

The present invention provides a method of treating mood disorders ofthe types discussed above. Diagnosis of these disorders, or theidentification of a patient at risk of one or more of them, is to bemade by a physician or psychiatrist. It is presently believed thatadministration of an effective dose of an anti-Aβ agent results in thealleviation of the effects of the disorder from which the subjectsuffers, or even the elimination of the disorder completely. Diagnosisof depression in Alzheimer's patients may be more challenging than inother elderly patients. Recent diagnostic criteria for depression inAlzheimer's disease will aid the diagnosis [Olin, et al., Am. J Geriatr.Psychiatry 10:125-128 and 129-141 (2002)].

Major Depressive Episode may be diagnosed according to the followingcriteria: A) five (or more) of the following symptoms have been presentduring the same 2-week period and represent a change from previousfunctioning; at least one of the symptoms is either (1) depressed moodor (2) loss of interest or pleasure (excluding symptoms that are clearlydue to a general medical condition, or mood-incongruent delusions orhallucinations): 1. depressed mood most of the day, nearly every day, asindicated by either subjective report (e.g., feels sad or empty) orobservation made by others (e.g., appears tearful); 2. markedlydiminished interest or pleasure in all, or almost all, activities mostof the day, nearly every day (as indicated by either subjective accountor observation made by others); 3. significant weight loss when notdieting or weight gain (e.g., a change of more than 5% of body weight ina month), or decrease or increase in appetite nearly every day; 4.insomnia or hypersomnia nearly every day; 5. psychomotor agitation orretardation nearly every day (observable by others, not merelysubjective feelings of restlessness or being slowed down); 6. fatigue orloss of energy nearly every day; 7. feelings of worthlessness orexcessive or inappropriate guilt (which may be delusional) nearly everyday (not merely self-reproach or guilt about being sick); 8. diminishedability to think or concentrate, or indecisiveness, nearly every day(either by subjective account or as observed by others); 9. recurrentthoughts of death (not just fear of dying), recurrent suicidal ideationwithout a specific plan, or a suicide attempt or a specific plan forcommitting suicide; B) the symptoms do not meet criteria for a MixedEpisode; C) the symptoms cause clinically significant distress orimpairment in social, occupational, or other important areas offunctioning; D) the symptoms are not due to the direct physiologicaleffects of a substance (e.g., a drug of abuse, a medication) or ageneral medical condition (e.g., hypothyroidism); and E) the symptomsare not better accounted for by Bereavement, i.e., after the loss of aloved one, the symptoms persist for longer than 2 months or arecharacterized by marked functional impairment, morbid preoccupation withworthlessness, suicidal ideation, psychotic symptoms, or psychomotorretardation.

Major Depressive Disorder (DSM-IV 296.3x) may be diagnosed according tothe following criteria: A) at least one of the following abnormal moodswhich significantly interfered with the person's life—1. abnormaldepressed mood most of the day, nearly every day, for at least 2 weeksor 2. abnormal loss of all interest and pleasure most of the day, nearlyevery day, for at least 2 weeks; B) at least five of the followingsymptoms have been present during the same 2 week depressed period: 1.abnormal depressed mood [as defined in criterion A]; 2. abnormal loss ofall interest and pleasure [as defined in criterion A2]; 3. abnormalweight gain or loss (when not dieting) or increase/decrease in appetite;4. sleep disturbance, either abnormal insomnia or abnormal hypersomnia;5. activity disturbance, either abnormal agitation or abnormal slowing(observable by others); 6. abnormal fatigue or loss of energy; 7.abnormal self-reproach or inappropriate guilt; 8. abnormal poorconcentration or indecisiveness; 9. abnormal morbid thoughts of death(not just fear of dying) or suicide; C) the symptoms are not due to amood-incongruent psychosis; D) there has never been a Manic Episode, aMixed Episode, or a Hypomanic Episode; E) the symptoms are not due tophysical illness, alcohol, medication, or street drugs; and F) thesymptoms are not due to normal bereavement.

Dysthymic disorder (DSM-IV 300.4) may be diagnosed according to thefollowing criteria: A) depressed mood for most of the day, for more daysthan not, as indicated either by subjective account or observation byothers, for at least 2 years; B) presence, while depressed, of two (ormore) of: poor appetite or overeating, insomnia or hypersomnia, lowenergy or fatigue, low self-esteem, poor concentration or difficultymaking decisions, and feelings of hopelessness; C) during the 2-yearperiod of the disturbance, the person has never been without thesymptoms in Criteria A and B for more than 2 months at a time; D) noMajor Depressive Episode has been present during the first 2 years ofthe disturbance; i.e., the disturbance is not better accounted for bychronic Major Depressive Disorder or Major Depressive Disorder inpartial remission (there may have been a previous Major DepressiveEpisode provided there was a full remission marked by there being nosignificant signs or symptoms for 2 months before development of theDysthymic Disorder. In addition, after the initial 2 years of DysthymicDisorder, there may be superimposed episodes of Major DepressiveDisorder, in which case both diagnoses may be given when the criteriaare met for a Major Depressive Episode.); E) there has never been aManic Episode, a Mixed Episode, or a Hypomanic Episode, and criteriahave never been met for Cyclothymic Disorder; F) the disturbance doesnot occur exclusively during the course of a chronic Psychotic Disorder,such as Schizophrenia or Delusional Disorder; G) the symptoms are notdue to the direct physiological effects of a substance (e.g., a drug ofabuse, a medication) or a general medical condition (e.g.,hypothyroidism); and H) the symptoms cause clinically significantdistress or impairment in social, occupational, or other important areasof functioning.

“Elderly subject” means a subject older than the average age ofmenopause for the species and culture (if relevant) of which the subjectis a member, assuming adequate nutrition and general health. The averageage of menopause for humans in the United States is 51 years of age [TheEndocrine Society, 4350 East West Highway, Suite 500, Bethesda, Md.20814-4426; www.endo-society.org]. The term “subject” or “patient” forpurposes of the present invention is any warm-blooded animal such as,but not limited to, a mouse, guinea pig, dog, horse, or human.Preferably, the subject is a mammal, more preferably rodent or primate,and most preferably, human.

“Administering” is the act of introducing a substance into the body of asubject, and may be achieved by oral, intravenous, intraperitoneal,subcutaneous, intramuscular, or intraparenchimal routes, among others.The antibodies are administered to a subject as identified herein usingstandard administration techniques, such as by intravenous,intraperitoneal, subcutaneous, pulmonary, transdermal, intramuscular,intranasal, buccal, sublingual, infusion, or suppository administration.The preferred routes of administration are intravenous, subcutaneous,and intraperitoneal. More preferred is either intravenous orsubcutaneous.

“Effective dose” means an amount of a substance that leads to measurableand beneficial effects, i.e. significant efficacy. The particulareffective amount or dose of compound administered according to thisinvention will of course be determined by the particular circumstancessurrounding the case, including the compound administered, the route ofadministration, the particular condition being treated, and similarconsiderations. A typical daily dose will contain from about 0.01 mg/kgto about 100 mg/kg of the active compound of this invention. Preferably,daily doses will be about 0.05 mg/kg to about 50 mg/kg, more preferablyfrom about 0.1 mg/kg to about 25 mg/kg. The frequency of dosing may bedaily or once, twice, three times or more per week or per month, asneeded to effectively treat the condition.

“Anti-Aβ antibody” means an immunoglobulin molecule (preferably an IgG)that recognizes, binds, and (or) sequesters Aβ peptide.

“Aβ peptide” and “Aβ ” refer to a peptide that is derived from amyloidprecursor protein (Alzheimer's disease amyloid A4 protein [Precursor],“APP”) by proteolytic cleavage. Full-length Aβ peptides are from 39 to43 amino acids long in humans, for example. Full length Aβ peptide mayundergo further cleavage in vivo to produce Aβ fragments that areshorter at the N-terminus, at the C-terminus, or both, by one to severalamino acids. Full-length Aβ peptide or fragments thereof may be usedalso as antigens to raise antibodies that bind Aβ peptide. Among themany Aβ peptide fragments used for this purpose, the Aβ13-28 fragment(conjugated via m-maleimidobenzoyl-N-hydroxysuccinimide ester to ananti-CD3 antibody) was used to raise antibody 266 [Seubert, P. et al.,Nature 359:325-327.(1992)].

“Conditions associated with Aβ” include clinical or pre-clinicalAlzheimer's disease, Down's syndrome, and chronic amyloid angiopathy[Grabowski T. J., et al., Ann. Neurol. 49: 697-705 (2001); Vinters H.V., Ann. Neurol. 49: 691-3 (2001)]. Regardless of the cause, thediagnosis of AD is made clinically by the finding of progressive memoryloss with increasing inability to participate in activities of dailyliving. Mild cognitive impairment may be associated with pre-clinicalAlzheimer's disease.

By “antibody” is meant a whole antibody, including without limitation ananimal-derived antibody (e.g., murine), chimeric, humanized, humansequence, recombinant, transgenic, grafted and single chain antibody,and the like, or any fusion proteins, conjugates, fragments, orderivatives thereof An antibody comprises protein resembling an antibodyin the broadest sense in that the protein comprises a binding site foran antigen, which binding site is comprised of three pairs ofcomplementarity determining regions. Antibody includes a wholeimmunoglobulin molecule, a monoclonal antibody, a chimeric antibody, ahumanized antibody; a human antibody, or an immunologically effectivefragment of any of these. An antibody fragment, or simply fragment,means an Fv, a disulfide linked Fv, scFv, Fab, Fab′, or F(ab′)₂fragment, which terms are well known in the art. In some contexts,herein, fragments will be mentioned specifically for emphasis;nevertheless, it will be understood that regardless of whether fragmentsare specified, the term “antibody” includes such fragments as well assingle-chain forms. As long as a protein retains the abilityspecifically to bind its intended target, it is included within the term“antibody.” Also included within the definition “antibody” are singlechain forms. Preferably, but not necessarily, the antibodies useful inthe invention are produced recombinantly. Antibodies may or may not beglycosylated, though glycosylated antibodies are preferred under somecircumstances, such as when prolonged residence in the body isdesirable, or when minimum risk of developing neutralizing antibodies.Antibodies, except perhaps for certain types in which cross-linkingbetween chains is accomplished by peptide or other chemical chains, areproperly cross-linked via disulfide bonds.

The basic antibody structural unit is known to comprise a tetramer. Eachtetramer is composed of two identical pairs of polypeptide chains, eachpair having one “light” (about 25 kDa) and one “heavy” chain (about50-70 kDa). The amino-terminal portion of each chain includes a variableregion of about 100 to 110 or more amino acids primarily responsible forantigen recognition. The carboxy-terminal portion of each chain definesa constant region primarily responsible for effector function.

Light chains are classified as kappa and lambda. Heavy chains areclassified as gamma, mu, alpha, delta, or epsilon, and define theantibody's isotype as IgG, IgM, IgA, IgD and IgE, respectively. IgGisotypes are preferred. Of the IgG subclasses, IgG1 and IgG4 arepreferred.

By “humanized antibody” is meant an antibody that is composed partiallyor fully of amino acid sequences derived from a human antibody germlineby altering the sequence of an antibody having non-human complementaritydetermining regions (CDR). A humanized immunoglobulin does not encompassa chimeric antibody, having a mouse variable region and a human constantregion. However, the variable region of the antibody and even the CDRare humanized by techniques that are by now well known in the art. Theframework regions of the variable regions are substituted by thecorresponding human framework regions leaving the non-human CDRsubstantially intact. As mentioned above, it is sufficient for use inthe methods of the invention, to employ an immunologically specificfragment of the antibody, including fragments representing single chainforms.

Preparation of antibodies for use in the present invention may becarried out by methods well known in the art, including preparingmonoclonal antibodies using well known techniques and screening for highaffinity antibodies, or by first identifying a monoclonal antibodyhaving reasonably high affinity and then improving the affinity usingwell known methods [e.g., U.S. Pat. Nos. 5,976,562, 5,824514, 5,817,483,5,814,476, 5,763,192, 5,723,323; WO97/29131; Huse, W. D., et al.,Internat'l Rev. Immunol. 10:129-137 (1993); Yelton, D. E., et al., J.Immunol. 155:1994-2004 (1995); Wu, H., et al., Proc. Natl. Acad. Sci.(USA) 95:6037-6042 (1998); Crameri, A., et al., Nature Medicine2:100-103 (1996); Stemmer, Proc. Natl. Acad. Sci. (USA) 91:10747-10751(1994); Stemmer, Nature 370:389-391 (1994), the portion of each of whichhaving to do with preparation of antibodies is incorporated herein byreference].

The antibodies used in the present invention will most advantageously beexpressed in recombinant hosts and purified using well known techniques[Page, M. J. & Sydenham, M. A., Bio/Technol. 9, 64-68 (1991); Carroll,A. R., et al., Mol. ininunol. 29, 821-827 (1992); Coloma, M. J., et al.,J. Immunol. Meth. 152, 89-104 (1992); Bebbington, C. R., et al.,Bio/Technol. 10, 169-175 (1992); Deyev, S., et al., FEBS Lett. 330,111-113 (1993); Bender, E., et al., Hum. Antibodies Hybridomas 4, 74-79(1993); Norderhaug, L., et al., J. Immunol. Meth. 204, 77-87 (1997);Poul, M. A., et al., Eur. J. Immunol. 25, 2005-2009 (1995), each ofwhich is incorporated herein by reference].

A preferred antibody for use in the present invention is 266, ahumanized form of 266, an antibody that binds to the same epitope on Aβthat 266 binds, any antibody comprised of the CDRs of 266, and anyantibody that competitively inhibits the binding of 266 and human Aβ.The skilled reader will know how to determine, from among many possiblemethods that are well known, whether any particular antibodycompetitively inhibits the binding of 266 and human Aβ. For example, acomparative ELISA method could be used. Wells of a 96-well ELISA plate(e.g., Nunc-Immuno plate, Cat #439454, NalgeNunc) are coated with Aβpeptide (1-42 is convenient, but other lengths could be used also),optionally conjugated to a larger protein such as albumin. After washingthe wells, they are blocked as appropriate, and then rinsed and driedappropriately. A mixture of biotinylated 266 antibody (e.g., mouse orhumanized; at 0.3 μg/ml final concentration, for example) and acompetitor antibody (starting at 750 μg/ml final concentration andserial 3-fold dilutions) are added in a final volume of 100 μl per well.No-competitor and background controls are run. The ELISA plate isincubated at an appropriate temperature for an appropriate length oftime, and then the wells are washed. After washing the wells,HRP-conjugated streptavidin (Cat #21124, Pierce), or equivalent, isadded to each well (e.g., 100 μl of 1 μg/ml). The plate is incubated atroom temperature for 30 min and washed. For color development, 100μl/well of ABTS Peroxidase Substrate (Kirkegaard & Perry Laboratories),or equivalent, is added. Color development is stopped and absorbance isread (e.g., at 415 nm). The absorbances are plotted against the log ofthe competitor concentration, curves are fitted to the data points(e.g., using Prism or equivalent) and the IC50 determined using methodswell known in the art. An antibody having an IC50 within about 100-foldof that of 266 is considered to competitively inhibit its binding.

Antibody 266 has the following amino acid sequences as CDRs: light chainCDR1:  1               5 Arg Ser Ser Gln Ser Leu Ile Tyr Ser (SEQ IDNO: 1) 10                  15 Asp Gly Asn Ala Tyr Leu His light chainCDR2:  1               5 Lys Val Ser Asn Arg Phe Ser (SEQ ID NO: 2)light chain CDR3: 1                5 Ser Gln Ser Thr His Val Pro Trp Thr(SEQ ID NO: 3) heavy chain CDR1:  1               5 Arg Tyr Ser Met Ser(SEQ ID NO: 4) heavy chain CDR2:  1               5 Gln Ile Asn Ser ValGly Asn Ser Thr (SEQ ID NO: 5) 10                  15 Tyr Tyr Pro AspThr Val Lys Gly and, heavy chain CDR3:  1 Gly Asp Tyr. (SEQ ID NO: 6)

In humanized versions of 266, human framework regions may optionallyhave substitutions of one to several residues from mouse 266 for thepurpose of maintaining the strength or specificity of the binding ofhumanized antibody 266 [see, Holtzman, et al., WO00/ 62801]. A preferredlight chain variable region of a humanized 266 antibody for use in thepresent invention has the following amino acid sequence:1                5                  10                   15 Asp Xaa ValMet Thr Gln Xaa Pro Leu Ser Leu Pro Val Xaa Xaa Gly (SEQ ID NO: 7)             20                  25                  30 Gln Pro Ala SerIle Ser Cys Arg Ser Ser Gln Ser Leu Xaa Tyr Ser         35                  40                  45 Asp Gly Asn Ala TyrLeu His Trp Phe Leu Gln Lys Pro Gly Gln Ser     50                  55                  60 Pro Xaa Leu Leu Ile TyrLys Val Ser Asn Arg Phe Ser Gly Val Pro 65                  70                  75                  80 Asp ArgPhe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile                 85                  90                  95 Ser Arg ValGlu Ala Glu Asp Xaa Gly Val Tyr Tyr Cys Ser Gln Ser            100                 105                 110 Thr His Val ProTrp Thr Phe Gly Xaa Gly Thr Xaa Xaa Glu Ile Lys Argwherein:

-   -   Xaa at position 2 is Val or Ile;    -   Xaa at position 7 is Ser or Thr;    -   Xaa at position 14 is Thr or Ser;    -   Xaa at position 15 is Leu or Pro;    -   Xaa at position 30 is Ile or Val;    -   Xaa at position 50 is Arg, Gln, or Lys;    -   Xaa at position 88 is Val or Leu;    -   Xaa at position 105 is Gln or Gly;    -   Xaa at position 108 is Lys or Arg; and    -   Xaa at position 109 is Val or Leu.

A preferred heavy chain variable region of a humanized 266 antibody foruse in the present invention has the following amino acid sequence: 1               5                  10                   15 Xaa Val GlnLeu Val Glu Xaa Gly Gly Gly Leu Val Gln Pro Gly Gly (SEQ ID NO: 8)             20                  25                  30 Ser Leu Arg LeuSer Cys Ala Ala Ser Gly Phe Thr Phe Ser Arg Tyr         35                  40                  45 Ser Met Ser Trp ValArg Gln Ala Pro Gly Lys Gly Leu Xaa Leu Val     50                  55                  60 Ala Gln Ile Asn Ser ValGly Asn Ser Thr Tyr Tyr Pro Asp Xaa Val65                  70                  75                  80 Lys GlyArg Phe Thr Ile Ser Arg Asp Asn Xaa Xaa Asn Thr Leu Tyr                 85                  90                  95 Leu Gln MetAsn Ser Leu Arg Ala Xaa Asp Thr Ala Val Tyr Tyr Cys            100                 105                 110 Ala Ser Gly AspTyr Trp Gly Gln Gly Thr Xaa Val Thr Val Ser Serwherein:

-   -   Xaa at position 1 is Glu or Gln;    -   Xaa at position 7 is Ser or Leu;    -   Xaa at position 46 is Glu, Val, Asp, or Ser;    -   Xaa at position 63 is Thr or Ser;    -   Xaa at position 75 is Ala, Ser, Val, or Thr;    -   Xaa at position 76 is Lys or Arg;    -   Xaa at position 89 is Glu or Asp; and    -   Xaa at position 107 is Leu or Thr.

A particularly preferred light chain variable region of a humanized 266antibody for use in the present invention has the following amino acidsequence: 1                5                  10                   15Asp Val Val Met Thr Gln Ser Pro Leu Ser Leu Pro Val Thr Leu Gly (SEQ IDNO: 9)              20                  25                  30 Gln ProAla Ser Ile Ser Cys Arg Ser Ser Gln Ser Leu Ile Tyr Ser         35                  40                  45 Asp Gly Asn Ala TyrLeu His Trp Phe Leu Gln Lys Pro Gly Gln Ser     50                  55                  60 Pro Arg Leu Leu Ile TyrLys Val Ser Asn Arg Phe Ser Gly Val Pro65                  70                  75                  80 Asp ArgPhe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile                 85                  90                  95 Ser Arg ValGlu Ala Glu Asp Val Gly Val Tyr Tyr Cys Ser Gln Ser            100                 105                 110 Thr His Val ProTrp Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys Arg.

A particularly preferred heavy chain variable region of a humanized 266antibody for use in the present invention has the following amino acidsequence:  1               5                   10                  15Glu Val Gln Leu Val Glu Ser Gly Gly Gly Leu Val Gln Pro Gly Gly (SEQ IDNO: 10)              20                  25                  30 Ser LeuArg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser Arg Tyr         35                  40                  45 Ser Met Ser Trp ValArg Gln Ala Pro Gly Lys Gly Leu Glu Leu Val     50                  55                  60 Ala Gln Ile Asn Ser ValGly Asn Ser Thr Tyr Tyr Pro Asp Thr Val 65                  70                  75                  80 Lys GlyArg Phe Thr Ile Ser Arg Asp Asn Ala Lys Asn Thr Leu Tyr                 85                  90                  95 Leu Gln MetAsn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys            100                 105                 110 Ala Ser Gly AspTyr Trp Gly Gln Gly Thr Leu Val Thr Val Ser Ser.

A preferred light chain for a humanized 266 antibody for use in thepresent invention has the amino acid sequence:  1              5                   10                   15 Asp Val ValMet Thr Gln Ser Pro Leu Ser Leu Pro Val Thr Leu (SEQ ID NO: 11)                 20                  25                   30 Gly Gln ProAla Ser Ile Ser Cys Arg Ser Ser Gln Ser Leu Ile                 35                  40                   45 Tyr Ser AspGly Asn Ala Tyr Leu His Trp Phe Leu Gln Lys Pro                 50                  55                   60 Gly Gln SerPro Arg Leu Leu Ile Tyr Lys Val Ser Asn Arg Phe                 65                  70                   75 Ser Gly ValPro Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp                 80                  85                   90 Phe Thr LeuLys Ile Ser Arg Val Glu Ala Glu Asp Val Gly Val                 95                  100                 105 Tyr Tyr CysSer Gln Ser Thr His Val Pro Trp Thr Phe Gly Gln                110                  115                 120 Gly Thr LysVal Glu Ile Lys Arg Thr Val Ala Ala Pro Ser Val                125                  130                 135 Phe Ile PhePro Pro Ser Asp Glu Gln Leu Lys Ser Gly Thr Ala                140                  145                 150 Ser Val ValCys Leu Leu Asn Asn Phe Tyr Pro Arg Glu Ala Lys                155                  160                 165 Val Gln TrpLys Val Asp Asn Ala Leu Gln Ser Gly Asn Ser Gln                170                  175                 180 Glu Ser ValThr Glu Gln Asp Ser Lys Asp Ser Thr Tyr Ser Leu                185                  190                 195 Ser Ser ThrLeu Thr Leu Ser Lys Ala Asp Tyr Glu Lys His Lys                200                  205                 210 Val Tyr AlaCys Glu Val Thr His Gln Gly Leu Ser Ser Pro Val                 215 ThrLys Ser Phe Asn Arg Gly Glu Cys.

A preferred heavy chain for a humanized 266 antibody for use in thepresent invention has the amino acid,sequence:  1              5                   10                   15 Glu Val GlnLeu Val Glu Ser Gly Gly Gly Leu Val Gln Pro Gly (SEQ ID NO: 12)                 20                  25                   30 Gly Ser LeuArg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser                 35                  40                   45 Arg Tyr SerMet Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu                 50                  55                   60 Glu Leu ValAla Gln Ile Asn Ser Val Gly Asn Ser Thr Tyr Tyr                 65                  70                   75 Pro Asp ThrVal Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ala                 80                  85                   90 Lys Asn ThrLeu Tyr Leu Gln Met Asn Ser Leu Arg Ala Glu Asp                 95                  100                 105 Thr Ala ValTyr Tyr Cys Ala Ser Gly Asp Tyr Trp Gly Gln Gly                110                  115                 120 Thr Leu ValThr Val Ser Ser Ala Ser Thr Lys Gly Pro Ser Val                125                  130                 135 Phe Pro LeuAla Pro Ser Ser Lys Ser Thr Ser Gly Gly Thr Ala                140                  145                 150 Ala Leu GlyCys Leu Val Lys Asp Tyr Phe Pro Glu Pro Val Thr                155                  160                 165 Val Ser TrpAsn Ser Gly Ala Leu Thr Ser Gly Val His Thr Phe                170                  175                 180 Pro Ala ValLeu Gln Ser Ser Gly Leu Tyr Ser Leu Ser Ser Val                185                  190                 195 Val Thr ValPro Ser Ser Ser Leu Gly Thr Gln Thr Tyr Ile Cys                200                  205                 210 Asn Val AsnHis Lys Pro Ser Asn Thr Lys Val Asp Lys Lys Val                215                  220                 225 Glu Pro LysSer Cys Asp Lys Thr His Thr Cys Pro Pro Cys Pro                230                  235                 240 Ala Pro GluLeu Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro                245                  250                 255 Lys Pro LysAsp Thr Leu Met Ile Ser Arg Thr Pro Glu Val Thr                260                  265                 270 Cys Val ValVal Asp Val Ser His Glu Asp Pro Glu Val Lys Phe                275                  280                 285 Asn Trp TyrVal Asp Gly Val Glu Val His Asn Ala Lys Thr Lys                290                  295                 300 Pro Arg GluGlu Gln Tyr Asn Ser Thr Tyr Arg Val Val Ser Val                305                  310                 315 Leu Thr ValLeu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys                320                  325                 330 Cys Lys ValSer Asn Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr                335                  340                 345 Ile Ser LysAla Lys Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr                350                  355                 360 Leu Pro ProSer Arg Asp Glu Leu Thr Lys Asn Gln Val Ser Leu                365                  370                 375 Thr Cys LeuVal Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu                380                  385                 390 Trp Glu SerAsn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro                395                  400                 405 Pro Val LeuAsp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys Leu                410                  415                 420 Thr Val AspLys Ser Arg Trp Gln Gln Gly Asn Val Phe Ser Cys                425                  430                 435 Ser Val MetHis Glu Ala Leu His Asn His Tyr Thr Gln Lys Ser                 440 LeuSer Leu Ser Pro Gly Lys.

Another preferred antibody for use in the present invention is an analogof 266, in which an N-glycosylation site within CDR2 of the heavy chain(SEQ ID NO:5) is engineered so as not to be glycosylated. Such an analogcomprises a light chain and a heavy chain, wherein the light chaincomprises the three light chain complementarity determining regions(CDRS) from mouse monoclonal antibody 266 (SEQ ID NO: 1-3), and whereinthe heavy chain comprises heavy chain CDR1 and CDR3 from mousemonoclonal antibody 266 (SEQ ID NO: 4 and 6, respectively), and a heavychain CDR2 having the sequence given by SEQ ID NO:13:  1               5Gln Ile Asn Ser Val Gly (SEQ ID NO: 13)              10 Xaa Xaa Xaa TyrTyr Pro          15 Asp Thr Val Lys Glywherein,

-   -   Xaa at position 7 is any amino acid, provided that if Xaa at        position 8 is neither Asp nor Pro and Xaa at position 9 is Ser        or Thr, then Xaa at position 7 is not Asn;    -   Xaa at position 8 is any amino acid, provided that if Xaa at        position 7 is Asn and Xaa at position 9 is Ser or Thr, then Xaa        at position 8 is Asp or Pro; and    -   Xaa at position 9 is any amino acid, provided that if Xaa at        position 7 is Asn and Xaa at position 8 is neither Asp nor Pro,        then Xaa at position 9 is neither Ser nor Thr.

By “any amino acid” is meant any naturally occurring amino acid.Preferred naturally-occurring amino acids are Ala, Cys, Asp, Glu, Phe,Gly, His, Ile, Lys, Leu, Met, Asn, Pro, Gln, Arg, Ser, Thr, Val, Trp,and Tyr.

A preferred group of antibodies are those having as light chainCDR1-CDR3 the sequences SEQ ID NO:1-3, respectively, as heavy chain CDR1and CDR3 the sequences SEQ ID NO:4 and 6, respectively, and wherein thesequence of heavy chain CDR2 is SEQ ID NO:13, wherein:

-   -   Xaa at position 7 of SEQ ID NO: 13 is selected from the group        consisting of Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu,        Met, Asn, Pro, Gln, Arg, Ser, Thr, Val, Trp, and Tyr, provided        that if Xaa at position 8 is neither Asp nor Pro and Xaa at        position 9 is Ser or Thr, then Xaa at position 7 is not Asn;    -   Xaa at position 8 of SEQ ID NO: 13 is selected from the group        consisting of Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu,        Met, Asn, Pro, Gln, Arg, Ser, Thr, Val, Trp, and Tyr, provided        that if Xaa at position 7 is Asn and Xaa at position 9 is Ser or        Thr, then Xaa at position 8 is Asp or Pro; and    -   Xaa at position 9 of SEQ ID NO:13.is selected from the group        consisting of Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu,        Met, Asn, Pro, Gln, Arg, Ser, Thr, Val, Trp, and Tyr, provided        that if Xaa at position 7 is Asn and Xaa at position 8 is        neither Asp nor Pro, then Xaa at position 9 is neither Ser nor        Thr.

Another description of the preferred group is: antibodies or fragmentsthereof having as light chain CDR1-CDR3 the sequences SEQ ID NO:1-3,respectively, as heavy chain CDR1 and CDR3 the sequences SEQ ID NO:4 and6, respectively, and wherein the sequence of heavy chain CDR2 isselected from the group consisting of:  1               5 Gln Ile AsnSer Val Gly (SEQ ID NO: 14)              10 Xaa Xaa Xaa Tyr Tyr Pro         15 Asp Thr Val Lys Glywherein:

-   -   Xaa at position 7 of SEQ ID NO:14 is selected from the group        consisting of Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu,        Met, Pro, Gln, Arg, Ser, Thr, Val, Trp, and Tyr;    -   Xaa at position 8 of SEQ ID NO:14 is selected from the group        consisting of Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu,        Met, Asn, Pro, Gln, Arg, Ser, Thr, Val, Trp, and Tyr; and

Xaa at position 9 of SEQ ID NO:14 is selected from the group consistingof Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu, Met, Asn, Pro, Gln,Arg, Ser, Thr, Val, Trp, and Tyr;  1               5 Gln Ile Asn Ser ValGly (SEQ ID NO: 15)              10 Xaa Xaa Xaa Tyr Tyr Pro          Asp Thr Val Lys Glywherein:

-   -   Xaa at position 7 of SEQ ID NO: 15 is Asn;    -   Xaa at position 8 of SEQ ID NO:15 is selected from the group        consisting of Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu,        Met, Asn, Pro, Gln, Arg, Ser, Thr, Val, Trp, and Tyr; and

Xaa at position 9 of SEQ ID NO:15 is selected from the group consistingof Ala, Cys, Asp, Glu, Phe, Gly, His, Ile, Lys, Leu, Met, Asn, Pro, Gln,Arg, Val, Trp, and Tyr; and (SEQ ID NO: 16)  1               5 Gln IleAsn Ser Val Gly Xaa Xaa Xaa 10                  15 Tyr Tyr Pro Asp ThrVal Lys Glywherein:

-   -   Xaa at position 7 of SEQ ID NO: 16 is Asn;    -   Xaa at position 8 of SEQ ID NO: 16 is selected from the group        consisting of Asp and Pro; and    -   Xaa at position 9 of SEQ ID NO: 16 is selected from the group        consisting of Ser and Thr.

Preferred sequences for CDR2 of the heavy chain include those in whichonly a single amino acid is changed, those in which only two amino acidsare changed, or all three are changed. It is preferred to replace Asn atposition 7, or to replace Thr at position 9, or to replace both.Conservative substitutions at one, two, or all three positions arepreferred. The most preferred species are those in which Asn at position7 is replaced with Ser or Thr.

Preferred deglycosylated 266 antibodies for use in the present inventionare those in which in CDR2 of the heavy chain (i.e., within SEQ ID NO:13, as described above):

-   -   Xaa at position 7 is selected from the group consisting of Ala,        Gly, His, Asn, Gln, Ser, and Thr, provided that if Xaa at        position 9 is Ser or Thr, then Xaa at position 7 is not Asn;    -   Xaa at position 8 is selected from the group consisting of Ala,        Gly, His, Asn, Gln, Ser, and Thr; and    -   Xaa at position 9 is selected from the group consisting of Ala,        Gly, His, Asn, Gln, Ser, and Thr, provided that if Xaa at        position 7 is Asn, then Xaa at position 9 is neither Ser nor        Thr.

An alternate description of preferred declycogsylated 266 antibodies is:antibodies or fragments thereof having as light chain CDRI-CDR3 thesequences SEQ ID NO:1-3, respectively, as heavy chain CDR1 and CDR3 thesequences SEQ ID NO:4 and 6, respectively, and wherein the sequence ofheavy chain CDR2 is selected from the group consisting of: (SEQ ID NO:17)  1               5 Gln Ile Asn Ser Val Gly Xaa Xaa Xaa10                  15 Tyr Tyr Pro Asp Thr Val Lys Glywherein:

-   -   Xaa at position 7 of SEQ ID NO: 17 is selected from the group        consisting of Ala, Gly, His, Gln, Ser, and Thr;    -   Xaa at position 8 of SEQ ID NO: 17 is selected from the group        consisting of Ala, Gly, His, Asn, Gln, Ser, and Thr; and

Xaa at position 9 of SEQ ID NO: 17 is selected from the group consistingof Ala, Gly, His, Asn, Gln, Ser, and Thr; and (SEQ ID NO: 18) 1               5 Gln Ile Asn Ser Val Gly Xaa Xaa Xaa10                  15 Tyr Tyr Pro Asp Thr Val Lys Glywherein:

-   -   Xaa at position 7 of SEQ ID NO: 18 is Asn;    -   Xaa at position 8 of SEQ ID NO:1 8 is selected from the group        consisting of Ala, Gly, His, Asn, Gln, Ser, and Thr; and    -   Xaa at position 9 of SEQ ID NO: 18 is selected from the group        consisting of Ala, Gly, His, Asn, and Gln.

A preferred humanized antibody for use in the present invention has thelight chain variable region of SEQ ID NO:7 and a heavy chain variableregion of SEQ ID NO:19 1               5                   10                   15 Xaa Val GlnLeu Val Glu Xaa Gly Gly Gly Leu Val Gln Pro Gly (SEQ ID NO: 19)                 20                  25                   30 Gly Ser LeuArg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser                 35                  40                   45 Arg Tyr SerMet Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu                 50                  55                   60 Xaa Leu ValAla Gln Ile Asn Ser Val Gly Xaa Xaa Xaa Tyr Tyr                 65                  70                   75 Pro Asp XaaVal Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Xaa                 80                  85                   90 Xaa Asn ThrLeu Tyr Leu Gln Met Asn Ser Leu Arg Ala Xaa Asp                 95                  100                 105 Thr Ala ValTyr Tyr Cys Ala Ser Gly Asp Tyr Trp Gly Gln Gly                 110 ThrXaa Val Thr Val Ser Serwherein:

-   -   Xaa at position 1 is Glu or Gln;    -   Xaa at position 7 is Ser or Leu;    -   Xaa at position 46 is Glu, Val, Asp, or Ser;    -   Xaa at position 56 is any amino acid, provided that if Xaa at        position 57 is neither Asp nor Pro and Xaa at position 59 is Ser        or Thr, then Xaa at position 56 is not Asn;    -   Xaa at position 57 is any amino acid, provided that if Xaa at        position 56 is Asn and Xaa at position 58 is Ser or Thr, then        Xaa at position 57 is Asp or Pro; and    -   Xaa at position 58 is any amino acid, provided that if Xaa at        position 56 is Asn and Xaa at position 57 is neither Asp nor        Pro, then Xaa at position 58 is neither Ser nor Thr    -   Xaa at position 63 is Thr or Ser;    -   Xaa at position 75 is Ala, Ser, Val, or Thr;    -   Xaa at position 76 is Lys or Arg;    -   Xaa at position 89 is Glu or Asp; and    -   Xaa at position 107 is Leu or Thr.

A preferred humanized antibody for use in the present invention has thelight chain variable region of SEQ ID NO:9 and a heavy chain variableregion of SEQ ID NO:20:1                5                   10                   15 Glu Val GlnLeu Val Glu Ser Gly Gly Gly Leu Val Gln Pro Gly (SEQ ID NO: 20)                 20                  25                   30 Gly Ser LeuArg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser                 35                  40                   45 Arg Tyr SerMet Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu                 50                  55                   60 Glu Leu ValAla Gln Ile Asn Ser Val Gly Xaa Xaa Xaa Tyr Tyr                 65                  70                   75 Pro Asp ThrVal Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ala                 80                  85                   90 Lys Asn ThrLeu Tyr Leu Gln Met Asn Ser Leu Arg Ala Glu Asp                 95                  100                 105 Thr Ala ValTyr Tyr Cys Ala Ser Gly Asp Tyr Trp Gly Gln Gly                 110 ThrLeu Val Thr Val Ser Ser.wherein:

-   -   Xaa at position 56 is any amino acid, provided that if Xaa at        position 57 is neither Asp nor Pro and Xaa at position 59 is Ser        or Thr, then Xaa at position 56 is not Asn;    -   Xaa at position 57 is any amino acid, provided that if Xaa at        position 56 is Asn and Xaa at position 58 is Ser or Thr, then        Xaa at position 57 is Asp or Pro; and    -   Xaa at position 58 is any amino acid, provided that if Xaa at        position 56 is Asn and Xaa at position 57 is neither Asp nor        Pro, then Xaa at position 58 is neither Ser nor Thr.

A preferred humanized antibody for use in the present invention has thelight chain variable region of SEQ ID NO:1 1 and a heavy chain given bySEQ ID NO:21:  1              5                   10                   15 Glu Val GlnLeu Val Glu Ser Gly Gly Gly Leu Val Gln Pro Gly (SEQ ID NO: 21)                 20                  25                   30 Gly Ser LeuArg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Ser                 35                  40                   45 Arg Tyr SerMet Ser Trp Val Arg Gln Ala Pro Gly Lys Gly Leu                 50                  55                   60 Glu Leu ValAla Gln Ile Asn Ser Val Gly Xaa Xaa Xaa Tyr Tyr                 65                  70                   75 Pro Asp ThrVal Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ala                 80                  85                   90 Lys Asn ThrLeu Tyr Leu Gln Met Asn Ser Leu Arg Ala Glu Asp                 95                  100                 105 Thr Ala ValTyr Tyr Cys Ala Ser Gly Asp Tyr Trp Gly Gln Gly                110                  115                 120 Thr Leu ValThr Val Ser Ser Ala Ser Thr Lys Gly Pro Ser Val                125                  130                 135 Phe Pro LeuAla Pro Ser Ser Lys Ser Thr Ser Gly Gly Thr Ala                140                  145                 150 Ala Leu GlyCys Leu Val Lys Asp Tyr Phe Pro Glu Pro Val Thr                155                  160                 165 Val Ser TrpAsn Ser Gly Ala Leu Thr Ser Gly Val His Thr Phe                170                  175                 180 Pro Ala ValLeu Gln Ser Ser Gly Leu Tyr Ser Leu Ser Ser Val                185                  190                 195 Val Thr ValPro Ser Ser Ser Leu Gly Thr Gln Thr Tyr Ile Cys                200                  205                 210 Asn Val AsnHis Lys Pro Ser Asn Thr Lys Val Asp Lys Lys Val                215                  220                 225 Glu Pro LysSer Cys Asp Lys Thr His Thr Cys Pro Pro Cys Pro                230                  235                 240 Ala Pro GluLeu Leu Gly Gly Pro Ser Val Phe Leu Phe Pro Pro                245                  250                 255 Lys Pro LysAsp Thr Leu Met Ile Ser Arg Thr Pro Gln Val Thr                260                  265                 270 Cys Val ValVal Asp Val Ser His Gln Asp Pro Gln Val Lys Phe                275                  280                 285 Asn Trp TyrVal Asp Gly Val Glu Val His Asn Ala Lys Thr Lys                290                  295                 300 Pro Arg GluGln Gln Tyr Asn Ser Thr Tyr Arg Val Val Ser Val                305                  310                 315 Leu Thr ValLeu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys                320                  325                 330 Cys Lys ValSer Asn Lys Ala Leu Pro Ala Pro Ile Gln Lys Thr                335                  340                 345 Ile Ser LysAla Lys Gly Gln Pro Arg Gln Pro Gln Val Tyr Thr                350                  355                 360 Leu Pro ProSer Arg Asp Gln Leu Thr Lys Asn Gln Val Ser Leu                365                  370                 375 Thr Cys LeuVal Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Gln                380                  385                 390 Trp Gln SerAsn Gly Gln Pro Gln Asn Asn Tyr Lys Thr Thr Pro                395                  400                 405 Pro Val LeuAsp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys Leu                410                  415                 420 Thr Val AspLys Ser Arg Trp Gln Gln Gly Asn Val Phe Ser Cys                425                  430                 435 Ser Val MetHis Gln Ala Leu His Asn His Tyr Thr Gln Lys Ser                 440 LeuSer Leu Ser Pro Gly Lyswherein:

-   -   Xaa at position 56 is any amino acid, provided that if Xaa at        position 57 is neither Asp nor Pro and Xaa at position 59 is Ser        or Thr, then Xaa at position 56 is not Asn;    -   Xaa at position 57 is any amino acid, provided that if Xaa at        position 56 is Asn and Xaa at position 58 is Ser or Thr, then        Xaa at position 57 is Asp or Pro; and    -   Xaa at position 58 is any amino acid, provided that if Xaa at        position 56 is Asn and Xaa at position 57 is neither Asp nor        Pro, then Xaa at position 58 is neither Ser nor Thr.

Preferred deglycosylated 266 antibodies having the heavy variable regionaccording to SEQ ID NO:19, SEQ ID NO:20, and SEQ ID NO:21 are thosewherein:

-   -   Xaa at position 56 is selected from the group consisting of Ala,        Gly, His, Asn, Gln, Ser, and Thr, provided that if Xaa at        position 58 is Ser or Thr, then Xaa at position 56 is not Asn;    -   Xaa at position 57 is selected from the group consisting of Ala,        Gly, His, Asn, Gin, Ser, and Thr; and    -   Xaa at position 58 is selected from the group consisting of Ala,        Gly, His, Asn, Gln, Ser, and Thr, provided that if Xaa at        position 56 is Asn, then Xaa at position 58 is neither Ser nor        Thr.

Preferred sequences for CDR2 (positions 56, 57, and 58) of the heavychain SEQ ID NO: 19, SEQ ID NO:20, and SEQ ID NO:21 include those inwhich only a single amino acid is changed, those in which only two aminoacids are changed, or all three are changed. It is preferred to replaceAsn at position 56. It is preferred to replace Thr at position 58 withan amino acid other than Ser. It is preferred to not destroy theN-glycosylation site in the CDR2 of the 266 heavy chain by replacing Serat position 57 with Pro or Asp. Conservative substitutions at one, two,or all three positions are preferred. The most preferred species arethose in which Asn at position 56 is replaced with Ser or Thr.Particularly preferred antibodies are those in which Ser or Thr is atposition 56, Ser is at position 57, and Thr is at position 58 of SEQ IDNO: 19, SEQ ID NO:20, or SEQ ID NO:21.

The most preferred species are antibodies comprising a light chain ofSEQ ID NO:11 and a heavy chain of SEQ ID NO:21, wherein in SEQ ID NO:21,Xaa at position 56 is Ser, Xaa at position 57 is Ser, and Xaa atposition 58 is Thr (“N56S”), or wherein in SEQ ID NO:21, Xaa at position56 is Thr, Xaa at position 57 is Ser, and Xaa at position 58 is Thr(“N56T”).

The preparation of an acceptable pharmaceutical preparation of theantibodies used in the present invention, including its strength,excipients, pH, isotonicity, presentation, dosage form, and the like, iswell known to the skilled person. Pharmaceutical compositions for use inthe present invention should be appropriate for the selected mode ofadministration, and pharmaceutically acceptable excipients such as,buffers, surfactants, preservatives, solubilizing agents, isotonicityagents, stabilizing agents and the like are used as appropriate.Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton Pa.,latest edition, incorporated herein by reference, provides a compendiumof formulation techniques as are generally known to practitioners.Pharmaceutical preparations for use in the present invention should besterile or at least nearly so, and if necessary preserved or renderedbacteriostatic.

The following example(s) are intended to illustrate, not limit, theinvention.

EXAMPLE 1

Adult, 11 month old females, wild type control and homozygous PDAPPtransgenic mice originating from a hybrid genetic background(DBA—C57BL/6—Swiss Webster) [Games et al., Nature. 373:523-527 (1995)],were tested. Approximately 50% of the mice from each genotype group (forsample sizes see tables herein) received 500 μg of mouse monoclonalantibody 266.2 and the other 50% of the mice received phosphate bufferedsaline (PBS) vehicle administered intra-peritoneally 9 days and 2 daysprior to start of behavioral experiments. The behavioral tests wereconducted in a fully. randomized and blind manner, i.e. the experimenterhad no knowledge of the genotype or the drug treatment history of thesubjects. Furthermore, mice were tested in four test chambers so that atany given time one mouse was being tested from each of the four (2genotypes×2 injection groups) groups. This way any potential circadianchanges must have affected all groups in an identical manner.

Prior to testing, and between testing days, animals were group housed (4mice per cage) in standard plastic cages (32.5×15×15 cm,length×width×depth) with sawdust bedding, and maintained on a 12/12 hrlight/dark cycle (lights on at 6 a.m.) with constant temperature (21°C.) and 45% relative humidity. Food and water were available ad libitum.

Four behavioral sessions (6 min each) were conducted over a four-dayperiod as described in detail [Fitch, et al., Hippocampus, 12: 4-17(2002)]. Briefly, on day one, a habituation session in a neutral contextwas conducted (behavior was not quantified). This was followed by atraining paradigm on day two. Subsequently, on day three, animals weretested in the context memory test and then finally, the cue memory testwas conducted on day four. Following each trial, animals were returnedto their home cage. Transgenic and wild type mice were randomly assignedto each of four fear conditioning chambers so that 2 transgenic (onetreated with the antibody and the other with vehicle) and two wild typemice (one treated with the antibody and the other with vehicle) wererunning concurrently exactly at the same time. Order of testing wasmaintained throughout the tests. Each animal was tested in the samechamber in which it was trained. Behavioral experimentation andquantification of data were done blind.

In the neutral context, all animals were exposed to a ‘safe’ environmentin which no shocks or tone cues were delivered. This environment was thebasic test chamber but visual and tactile contextual cues of the chamberwere altered by replacing the shock grid with a perforated acrylic sheetand by installing wall inserts (yellow cartoon paper) inside the cage.Fresh bedding was placed in the drop pan underneath the floor cover ofthe chamber to provide a familiar (home cage) smell. Between mice thechamber was cleaned with Petzyme (Petsmart, Pacific Coast Distributing,Phoenix, Ariz.). This same ‘neutral context’ was later used for testingtone cue responses. After having been exposed to the neutral context,mice were placed into the test chamber designated ‘unsafe’ where thewall inserts and acrylic floor were removed. Bedding was removed fromthe drop pan and the chamber and drop pan were cleaned with Steris (St.Louis, Mo.) ‘Coverage Spray’ disinfectant before each subject trial. Byusing the neutral and unsafe contexts we hoped to facilitatediscrimination of relevant contextual cues from other cues, e.g. humanhandling or cues of the test room, which were always present and whichshould not be associated with the shock. In the unsafe context(training) subjects were given 10-15 s to acclimatize before behavioralrecording was begun. For the first 160 s of the training no stimulationwas administered. This adaptation period was followed by a 20 s tone cue(80 db, 3000 Hz), which was co-terminated with a 1 sec 0.7 mA scrambledelectric foot shock. This stimulus presentation was repeated at 220 sand again at 280 s for a total of three tone/shock pairings during the360 s long training session.

The following day, contextual-cues-elicited fear responses were recordedfor a 360 s period in the chamber in which training was previouslyconducted (unsafe context). No tone or shock was presented during thiscontext test. Between individual subject trials, chambers were cleanedwith ‘Petzyme’, an agent that provided a novel odor cue. The change incleaning agents was made in order to minimize the possibility of miceusing a salient olfactory cue to identify the unsafe context and thusexhibit their response based on elemental rather than contextualinformation.

On the final day of the paradigm, elemental tone cue-associated learningwas tested in the safe neutral chamber with wall inserts and acrylicfloor cover present, and with clean bedding in the drop pan beneath thefloor. During this cue test, animals were presented with tone cuesidentical in amplitude, frequency, and timing of delivery to those givenduring training, however, no shock was administered. Following eachtraining or test trial, animals were returned to their home cages.

Behavior of the mice was video-recorded with Camcorders (Sony, DCRTRV-20 mini DVCam) and later replayed on a digital VCR (Sony DVCAMDSR-20 digital VCR). Quantification of behavior was conducted usingObserver Video Pro software (Noldus, Vageningen, The Netherlands). Thesoftware allows the experimenter to quantify predefined motor andposture patterns. The software also makes it possible for theexperimenter to control the digital VCR and to synchronize thecomputer's internal clock with the time stamp generated by the VCR. Thefollowing behavioral parameter is quantified: lonz-body (also known inthe literature as “stretch attend posture”), hind paws are anchoredwhile the front of the body is moving forward, body is elongated(stretched) and is kept very close to the ground. For the trainingsession the relative duration of long-body was calculated for twointervals, the period preceding the first shock (0-179 sec, neutralacclimation period) and the period including and following the firstshock (179-360 sec, period during which subjects experience pain due toelectric shock). For the context test, data are expressed for a singleinterval, the entire period (0-360 sec, period during which subjectsexperience fear due to presence of contextual stimuli). For the cuetest, data are expressed again for two intervals, for the periodpreceding the first tone cue (0-160 sec, period during which no signs ofdanger are present) and for the period following this (160-360 sec, aperiod during which tone cues previously associated with the shock aredelivered).

Statistical analyses were conducted using SYSTAT 10 statistical softwarepackage on a Compaq PC. Three-way or two-way repeated measures analysisof variance (ANOVA) was conducted to test the effects of genotype (wildtype or transgenic), the effects of injection (antibody or vehiclecontrol) and interval, which is the repeated measure factor.

For the training session, significant genotype, antibody, and intervaleffects were found (Table 1). The interaction terms interval x genotypeand interval x genotype x antibody were also significant. TABLE 1Relative duration of Long Body in Training (% ± SEM) Genotype +Treatment n 0-179 sec 179-360 sec Wild Type + vehicle 9 1.5 ± 0.8 34.9 ±4.1 Wild Type + anti-Aβ antibody 9 0.3 ± 0.3 18.3 ± 4.8 PDAPP + vehicle12 9.6 ± 4.1 46.0 ± 5.5 PDAPP + anti-Aβ antibody 12 1.1 ± 0.6 43.2 ± 4.7Source SS df MS F p Univariate Repeated Measures Analysis - BetweenSubjects Genotype 2581 1 2581 14.1 0.001 Antibody 1076 1 1076 5.86 0.020Genotype *Antibody 54 1 54 0.294 0.591 Error 6980 38 184 UnivariateRepeated Measures Analysis - Within Subjects Interval 21687 1 21687 1610.000 Interval *Genotype 945 1 945 7.02 0.012 Interval *Antibody 116 1116 0.86 0.360 Interval *Genotype 576 1 576 4.27 0.046 *Antibody Error5117 38 135

Briefly, long-body posture was almost entirely absent before electricshocks were administered, confirming that under baseline condition, i.e.without the presence of pain or fear, mice do not exhibit this behavior.Interestingly, PDAPP transgenic mice did show some appreciable level oflong-body posture even during the first period of training when noshocks were given, but this was significantly reduced by the antibodytreatment. In response to electric shocks a significant increase oflong-body posture is observed in all mice, but this increase wassomewhat smaller in wild type animals compared to PDAPP transgenic mice.Furthermore, antibody treated mice, especially the wild type mice,showed a blunted increase of long-body posture.

Similar to the training session, significant antibody effects wereobserved id the context test and the effect of transgene was alsosignificant (Table 2). TABLE 2 Relative duration of Long Body in Context(% ± SEM) Genotype + Treatment n 0-360 sec Wild Type + vehicle 9 7.8 ±2.1 Wild Type + anti-Aβ antibody 9 3.5 ± 1.1 PDAPP + vehicle 12 20.2 ±3.9  PDAPP + anti-Aβ antibody 12 11.7 ± 2.3  Univariate RepeatedMeasures Analysis - Between Subjects Source SS df MS F p Genotype 1095 11095 13.5 0.001 Antibody 417 1 417 5.14 0.029 Genotype *Antibody 47.8 147.8 0.589 0.448 Error 3084 38 81.2

The antibody reduced long-body posture in the PDAPP mice almost to thelevel of the vehicle injected wild type mice. But it is also notablethat the antibody had a similar long-body posture reducing effect evenwhen injected in the wild type mice as compared to vehicle injected wildtype mice. Variance analysis showed that indeed the effect of thetransgene and the effect of the antibody injection did not interact witheach other (Table 2, transgene×antibody interaction is non-significant),i.e. the presence of the transgene increased, while antibody injectiondecreased the amount of long-body posture exhibited.

In the cue test a similar pattern of results was seen but the effectswere not statistically significant (Table 3), most probably due to thefact that in this test long-body posture was hardly seen. Nevertheless,the effect of antibody treatment was close to significance (p=0.065).TABLE 3 Relative duration of Long Body in Cue test (% ± SEM) Genotype +Treatment n 0-160 sec 160-360 sec Wild Type + vehicle 9 1.1 ± 0.5 1.4 ±0.8 Wild Type + anti-Aβ antibody 9 0.4 ± 0.4 0.7 ± 0.7 PDAPP + vehicle12 3.1 ± 1.3 3.1 ± 1.6 PDAPP + anti-Aβ antibody 12 0.9 ± 0.4 1.1 ± 0.5Source SS df MS F p Univariate Repeated Measures Analysis - BetweenSubjects Genotype 27.7 1 27.7 2.34 0.135 Antibody 42.7 1 42.7 3.60 0.065Genotype *Antibody 9.90 1 9.90 0.836 0.366 Error 450 38 11.8 UnivariateRepeated Measures Analysis - Within Subjects Interval 0.780 1 0.7800.113 0.739 Interval *Genotype 0.295 1 0.295 0.042 0.837 Interval*Antibody 0.059 1 0.059 0.009 0.927 Interval *Genotype 0.105 1 0.1050.015 0.903 *Antibody Error 262 38 6.90

The fear conditioning paradigm allowed us to investigate shock,contextual stimuli, or tone cue induced behavioral responses.Furthermore, software aided event recording made it possible for us toquantify a posture pattern, long-body, which is associated with fear.This behavior showed a consistent increase in PDAPP mice as compared towild type control. This increase may be due to Aβ deposition oroverexpression of the mutant form of APP in the transgenic mice.Consistent with this, but also surprisingly, our analysis also revealeda significant long-body posture reducing effect of the anti-Aβ antibodytreatment.

Note the elevated amount of long-body posture exhibited in response tothe three shock-tone pairing during the second half of the trainingsession (3-6 min). This behavior is believed to be the expression of amild level of anxiety. Also note the consistent reduction of thisbehavior by antibody treatment in both genotype groups.

Long-body posture has been observed under aversive conditions in micewhen cues associated with natural predators are present [Blanchard, etal., Risk assessment and animal models of anxiety. In: Olivier et al.(eds.) Animal models in psychopharmacology. Advances in pharmacologicalsciences. Basel: Birkhauser Verlag. pp. 117-134 (1991)]. This behavioris also evoked in mice by other fear inducing stimuli including electricshocks or the context in which the shocks were delivered [Fitch, et al.2002; Gerlai, et al., J. Neuroscience 19:9538-9549 (1999)]. Thus,long-body has been interpreted as a sign of fear [Blanchard, et al.(1991); Fitch, et al. (2002); Gerlai, et al. (1999)]. Accordingly,increased long-body posture may in fact represent increased fear inPDAPP mice compared to wild type control, and decreased long-bodyposture elicited by the injection of anti-Aβ antibody may representreduction of fear.

It is important to emphasize that the decrease of long-body posture wasobserved both in PDAPP mice and also in wild type control. This suggeststhat perhaps Aβ lowering may have a beneficial, i.e. anxiolytic, effectsnot only in AD patients but perhaps in the non-demented elderlypopulation as well. Our present results thus raise a new and unexpectedpossibility: anti-Aβ agents may represent a novel therapeuticapplication in the treatment of anxiety and related disorders.

1-24. (canceled)
 25. A method for treating an anxiety disorder or a mooddisorder in an elderly subject, comprising administering to the subjectan effective dose of an anti-Aβ antibody:
 26. The method of claim 25,wherein the subject is diagnosed or is suspected to have a conditionrelated to Aβ, such as Alzheimer's disease or chronic amyloidangiopathy.
 27. The method of claim 25, wherein the subject is notdiagnosed or suspected to be suffering from a condition related to Aβ.28. The method of claim 25, wherein the subject is a human.
 29. Themethod of claim 25, wherein the disorder is a mood disorder.
 30. Themethod of claim 29, wherein the disorder is selected from the groupconsisting of depression, major depression, minor depression, majordepressive episode, and unipolar major depression.
 31. The method ofclaim 29, wherein the disorder is schizophrenia.
 32. The method of claim25, wherein the disorder is an anxiety disorder.
 33. The method of claim32, wherein the disorder is simple phobia.
 34. The method of claim 32,wherein the disorder is social phobia.
 35. The method of claim 32,wherein the disorder is agoraphobia.
 36. The method of claim 32, whereinthe disorder is panic disorder.
 37. The method of claim 32, wherein thedisorder is obsessive-compulsive disorder.
 38. The method of claim 32,wherein the disorder is post-traumatic stress disorder.
 39. The methodof claim 25, wherein the elderly subject is a human whose age is atleast 55 years, 60 years, 65, years, 70 years, 75 years, 80 years, 85,years, 90 years, 95 years, 100 years, 105 years, or 110 years.
 40. Themethod of claim 25, wherein the anti-Aβ antibody is a human or humanizedantibody.
 41. The method of claim 25, wherein the anti-Aβ antibodyrecognizes or binds to an epitope within between amino acids 1 and 28 ofhuman Aβ.
 42. The method of claim 25, wherein the anti-Aβ antibodyrecognizes or binds to an epitope within between amino acids 13 and 28of human Aβ.
 43. The method of claim 25, wherein the anti-Aβ antibody isselected from the group consisting of 266, N56S, N56T, any antibodycomprised of the CDRs of 266, N56S, or N56T, and any antibody thatcompetitively inhibits the binding of 266, N56S, or N56T and human Aβ.44. The method of claim 42, wherein the anti-Aβ antibody is selectedfrom the group consisting of: an antibody comprised of SEQ ID NO:7 andSEQ ID NO:8; an antibody comprised of SEQ ID NO:9 and SEQ ID NO: 10; anantibody comprised of SEQ ID NO: 11 and SEQ ID NO: 12; an antibodycomprised of SEQ ID NO:7 and SEQ ID NO: 19; an antibody comprised of SEQID NO:9 and SEQ ID NO:20; and an antibody comprised of SEQ ID NO:11 andSEQ ID NO:21.